Re: [SLUG] Swap = 2xRAM
Could you provide a link to the source/s that informed you of this? On 28/02/07, Howard Lowndes [EMAIL PROTECTED] wrote: I think I have just found a reason why the default installation often makes swap = 2xRAM. It's to do with laptops mainly. When they hibernate they apparently roll the memory image out to the swap space, hence the recommendation about the swap space size. -- Howard. LANNet Computing Associates - Your Linux people http://lannetlinux.com When you want a computer system that works, just choose Linux; When you want a computer system that works, just, choose Microsoft. -- Flatter government, not fatter government; abolish the Australian states. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html -- There is nothing more worthy of contempt than a man who quotes himself - Zhasper, 2004 -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Swap = 2xRAM
Right. So you're saying that desktop installers set swap to be 2x RAM by default, just in case the user decides to download suspend2, which didn't exist at the time the installer was written and isn't included in the distro, and *then* chooses to suspend to swap? I don't follow your argument. Why would an installer have default settings based on optional behaviour of a program that isn't even included in the distro and requires recompiling the kernel to use? On 28/02/07, Howard Lowndes [EMAIL PROTECTED] wrote: http://www.linux.com/article.pl?sid=06/05/24/1716222 If you select Swap Writer, suspend2 will write all data to the swap space, so make sure your swap is at least twice the amount of your RAM in size. You can also select File Writer and save the suspend data on a file on the hard disk instead, but I prefer the swap method since it's easier to set up. Compile, install your kernel, and reboot to it. Zhasper wrote: Could you provide a link to the source/s that informed you of this? On 28/02/07, Howard Lowndes [EMAIL PROTECTED] wrote: I think I have just found a reason why the default installation often makes swap = 2xRAM. It's to do with laptops mainly. When they hibernate they apparently roll the memory image out to the swap space, hence the recommendation about the swap space size. -- Howard. LANNet Computing Associates - Your Linux people http://lannetlinux.com When you want a computer system that works, just choose Linux; When you want a computer system that works, just, choose Microsoft. -- Flatter government, not fatter government; abolish the Australian states. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html -- Howard. LANNet Computing Associates - Your Linux people http://lannetlinux.com When you want a computer system that works, just choose Linux; When you want a computer system that works, just, choose Microsoft. -- Flatter government, not fatter government; abolish the Australian states. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html -- There is nothing more worthy of contempt than a man who quotes himself - Zhasper, 2004 -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Swap = 2xRAM
On Wed, 2007-02-28 at 10:06 +1100, Howard Lowndes wrote: http://www.linux.com/article.pl?sid=06/05/24/1716222 If you select Swap Writer, suspend2 will write all data to the swap space, so make sure your swap is at least twice the amount of your RAM in size. You can also select File Writer and save the suspend data on a file on the hard disk instead, but I prefer the swap method since it's easier to set up. Compile, install your kernel, and reboot to it. In earlier versions, swsusp required swap to be physical RAM + video RAM. And the recommendation was to make it a bit bigger, er, Just In Case. The suspend2 HOWTO[1] says requirements for using the swapwriter are spare swap = physical RAM. That's spare swap. The kernel will do its best to free up buffers and swap pages back in to make room for the swapwriter if it needs to. But yeah, sure, double your RAM to be on the safe side. I didn't know swsusp had a filewriter method these days. If I were setting it up right now I'd probably prefer going that way - relying on having enough free swap to suspend sounds kind of fragile. [1] - http://www.suspend2.net/HOWTO-2.html#ss2.2 Cheers, -- Pete -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Swap = 2xRAM
On 28/02/07, Howard Lowndes [EMAIL PROTECTED] wrote: Zhasper wrote: Right. So you're saying that desktop installers set swap to be 2x RAM by default, just in case the user decides to download suspend2, which didn't exist at the time the installer was written and isn't included in the distro, and *then* chooses to suspend to swap? I don't follow your argument. Why would an installer have default settings based on optional behaviour of a program that isn't even included in the distro and requires recompiling the kernel to use? Well, I have a default installation of FC6 on my laptop and that hibernates by rolling out to swap. Since the default installation has no idea what the capabilities are of the target hardware, it strikes me as being a reasonable assumption to configure swap thus. That's a much better reason for thinking that than the article you mentioned is :) Thanks! On 28/02/07, Howard Lowndes [EMAIL PROTECTED] wrote: http://www.linux.com/article.pl?sid=06/05/24/1716222 If you select Swap Writer, suspend2 will write all data to the swap space, so make sure your swap is at least twice the amount of your RAM in size. You can also select File Writer and save the suspend data on a file on the hard disk instead, but I prefer the swap method since it's easier to set up. Compile, install your kernel, and reboot to it. Zhasper wrote: Could you provide a link to the source/s that informed you of this? On 28/02/07, Howard Lowndes [EMAIL PROTECTED] wrote: I think I have just found a reason why the default installation often makes swap = 2xRAM. It's to do with laptops mainly. When they hibernate they apparently roll the memory image out to the swap space, hence the recommendation about the swap space size. -- Howard. LANNet Computing Associates - Your Linux people http://lannetlinux.com When you want a computer system that works, just choose Linux; When you want a computer system that works, just, choose Microsoft. -- Flatter government, not fatter government; abolish the Australian states. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html -- Howard. LANNet Computing Associates - Your Linux people http://lannetlinux.com When you want a computer system that works, just choose Linux; When you want a computer system that works, just, choose Microsoft. -- Flatter government, not fatter government; abolish the Australian states. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html -- Howard. LANNet Computing Associates - Your Linux people http://lannetlinux.com When you want a computer system that works, just choose Linux; When you want a computer system that works, just, choose Microsoft. -- Flatter government, not fatter government; abolish the Australian states. -- There is nothing more worthy of contempt than a man who quotes himself - Zhasper, 2004 -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Swap = 2xRAM
quote who=Howard Lowndes I think I have just found a reason why the default installation often makes swap = 2xRAM. It's to do with laptops mainly. When they hibernate they apparently roll the memory image out to the swap space, hence the recommendation about the swap space size. No, the 2*RAM thing comes from the distant past, back when the 2.2 and 2.4 VMs were lame. You don't need 2*RAM for laptop hibernate -- all the laptop needs is system (and sometimes video) memory written to disk, and with the current hibernate code, it's gzipped on the way in. (Your disk is slower than your CPU, so compressing to disk makes a *lot* of sense.) So, systems that still do 2*RAM by default do not do it for this reason (consider also that RHEL, not exactly primarily used with laptops, still leads the charge for 2*RAM). - Jeff -- Open CeBIT 2007: Sydney, Australia http://www.opencebit.com.au/ Thanks for watching, I'm Katie Couric... and I'm not just for breakfast anymore. - Katie Couric on Letterman -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Swap = 2xRAM
Jeff Waugh wrote: No, the 2*RAM thing comes from the distant past, back when the 2.2 and 2.4 VMs were lame. You don't need 2*RAM for laptop hibernate -- all the laptop needs is system (and sometimes video) memory written to disk, and with the current hibernate code, it's gzipped on the way in. (Your disk is slower than your CPU, so compressing to disk makes a *lot* of sense.) So, systems that still do 2*RAM by default do not do it for this reason (consider also that RHEL, not exactly primarily used with laptops, still leads the charge for 2*RAM). That's a bit unfair, FC6's installer suggested swap = RAM when I installed it on a Intel Mac Mini with 2GB of RAM. (I used FC6 since it 'just works' in the Mac Mini's EFI environment). I doubled it manually simply because I remembered how painful the 2.2--2.4 move was when the swap requirement became double the amount of RAM. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Swap = 2xRAM
quote who=Glen Turner (consider also that RHEL, not exactly primarily used with laptops, still leads the charge for 2*RAM). That's a bit unfair, FC6's installer suggested swap = RAM when I installed it on a Intel Mac Mini with 2GB of RAM. Fedora != RHEL (Fedora is way cooler because it has a community, and as we all know, the biggest community always wins). - Jeff -- Open CeBIT 2007: Sydney, Australia http://www.opencebit.com.au/ ... *bounce*bounce*bounce* -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
